upload sdk

git-svn-id: svn://kolibrios.org@4349 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/math/ef_fmod.c

@@ -0,0 +1,113 @@
+/* ef_fmod.c -- float version of e_fmod.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice 
+ * is preserved.
+ * ====================================================
+ */
+
+/* 
+ * __ieee754_fmodf(x,y)
+ * Return x mod y in exact arithmetic
+ * Method: shift and subtract
+ */
+
+#include "fdlibm.h"
+
+#ifdef __STDC__
+static const float one = 1.0, Zero[] = {0.0, -0.0,};
+#else
+static float one = 1.0, Zero[] = {0.0, -0.0,};
+#endif
+
+#ifdef __STDC__
+	float __ieee754_fmodf(float x, float y)
+#else
+	float __ieee754_fmodf(x,y)
+	float x,y ;
+#endif
+{
+	__int32_t n,hx,hy,hz,ix,iy,sx,i;
+
+	GET_FLOAT_WORD(hx,x);
+	GET_FLOAT_WORD(hy,y);
+	sx = hx&0x80000000;		/* sign of x */
+	hx ^=sx;		/* |x| */
+	hy &= 0x7fffffff;	/* |y| */
+
+    /* purge off exception values */
+	if(FLT_UWORD_IS_ZERO(hy)||
+	   !FLT_UWORD_IS_FINITE(hx)||
+	   FLT_UWORD_IS_NAN(hy))
+	    return (x*y)/(x*y);
+	if(hx<hy) return x;			/* |x|<|y| return x */
+	if(hx==hy)
+	    return Zero[(__uint32_t)sx>>31];	/* |x|=|y| return x*0*/
+
+    /* Note: y cannot be zero if we reach here. */
+
+    /* determine ix = ilogb(x) */
+	if(FLT_UWORD_IS_SUBNORMAL(hx)) {	/* subnormal x */
+	    for (ix = -126,i=(hx<<8); i>0; i<<=1) ix -=1;
+	} else ix = (hx>>23)-127;
+
+    /* determine iy = ilogb(y) */
+	if(FLT_UWORD_IS_SUBNORMAL(hy)) {	/* subnormal y */
+	    for (iy = -126,i=(hy<<8); i>=0; i<<=1) iy -=1;
+	} else iy = (hy>>23)-127;
+
+    /* set up {hx,lx}, {hy,ly} and align y to x */
+	if(ix >= -126) 
+	    hx = 0x00800000|(0x007fffff&hx);
+	else {		/* subnormal x, shift x to normal */
+	    n = -126-ix;
+	    hx = hx<<n;
+	}
+	if(iy >= -126) 
+	    hy = 0x00800000|(0x007fffff&hy);
+	else {		/* subnormal y, shift y to normal */
+	    n = -126-iy;
+	    hy = hy<<n;
+	}
+
+    /* fix point fmod */
+	n = ix - iy;
+	while(n--) {
+	    hz=hx-hy;
+	    if(hz<0){hx = hx+hx;}
+	    else {
+	    	if(hz==0) 		/* return sign(x)*0 */
+		    return Zero[(__uint32_t)sx>>31];
+	    	hx = hz+hz;
+	    }
+	}
+	hz=hx-hy;
+	if(hz>=0) {hx=hz;}
+
+    /* convert back to floating value and restore the sign */
+	if(hx==0) 			/* return sign(x)*0 */
+	    return Zero[(__uint32_t)sx>>31];	
+	while(hx<0x00800000) {		/* normalize x */
+	    hx = hx+hx;
+	    iy -= 1;
+	}
+	if(iy>= -126) {		/* normalize output */
+	    hx = ((hx-0x00800000)|((iy+127)<<23));
+	    SET_FLOAT_WORD(x,hx|sx);
+	} else {		/* subnormal output */
+	    /* If denormals are not supported, this code will generate a
+	       zero representation.  */
+	    n = -126 - iy;
+	    hx >>= n;
+	    SET_FLOAT_WORD(x,hx|sx);
+	    x *= one;		/* create necessary signal */
+	}
+	return x;		/* exact output */
+}